Aerosol generator



Aug. 19, 1952 1. w. HESSION, JR 2,607,574

AEROSOL GENERATOR Filed Feb. 26, 194'? s Shets-Sheefc 1 4 INVENTOR I Jsdn W HESS/O/LJ}:

ATTORNEYS g- 19, 1952 J. w. HESSION, JR 2,607,574

AEROSOL GENERATOR Filed Feb. 26, 1947 5 Sheets-Sheet 2 ATTORNEYS g- 19, 1952 J. w. HESSION, JR 2,607,574

AEROSOL GENERATOR Filed Feb. 26, 1947 5 Sheets-Sheet 5 INVENTOVR John M/. Hassle/2J1 ATTORNEY 5' A g- 19, 1952 J. W. HESSION, JR 2,607,574

AEROSOL GENERATOR Filed Feb. 26, 1947 5 Sheets-Sheet 4 I, I lNVE NTOR J 9 BaY n ess M [aw-Mk ATTORNEYS Aug. 19, 1952 J. w. HESSION, JR 2,507,574

' AEROSOL GENERATOR I Filed Feb. 26, 1947 5 Sheets-sheet 5 "1, "l ll l/ 4a INVENTOR v John 14/ f/essionJr:

BY M Maa/ ATTORNEYS Patented Aug. 19, 1952 UNITED STATES QFFICE r 2,607,574. a v

AEROSOL GENERATOR I J chn W.'Hession, Jr., Darien, Conn. ApplicationFebruary 26, 1947, Serial No; 973L128,-

. l This invention relates to aerosol generators and more particularly to a machine designed to effect a dispersion or diffusion of a selected liquid into particles which are extremely minute and substantially homogeneous in sizeand adapted to be readily air-borne for substantial distances. This application has certain features in common with my copending application Serial Number 654,610, filed Marchlfi, 1946.

The term aerosol is generally acceptedscientific circles as a generic termto describe the size of particles which maybe air -borne in varying degrees. Air-borne or aerosol particles may vary in size from one-tenth (.1) micron diameter or less, to upwards of fifty (50) microns diameter. The extent to which an aerosol particlemay be air-borne varies with its size or mass. As a rough approximation, it may be said that the cubic mass of a particle is approximately the cube of its diameter, and accordingly a par.- ticle which is one hundred (100) microns in diameter would possess approximately one thousand times the cubic mass of a particle of ten microns diameter. a

The drift of fine particles iii-normal aircurrents is largely determined by-the size of the particle, or more-particularly, its cubic mass. According to Stokes law of falling particles, it

has been determined that in a medium of still air, a particle of six microns in diameter will require approximately five minutes to fall one foot or thirty centimeters; a particle of ten microns diameter will require approximately two minutes to fall thirtycentimeters; a particle of twenty microns diameter will require approximately'onein r 9 Claims. (01. 261-90) halfminuteto fall thirty centimeters; while a particle of sixty microns diameter will require approximately three seconds to fall thirty centimeters. Aerosol particles which are fifty microns and larger in diameter normally remain suspended in air for a relatively short time period, will drift comparatively very short distances only,

and may be aptly classified as sprays. Therefore agents, hormones and 'medica'ments of the great-' 1 est importance to agriculture, industry and public health. The particle size of the diffused liquid in many instances determines theeffectiveness of theli'quid treatment, the quantity or volume of liquid necessary 'to effect the treatment, the

2 area over which the dispersed liquid is effective, theuniformity of deposition and concentration, the cost of effecting the dispersion and the avoidance of concentrations to a degree which are harmful or objectionable.

In the field of entomology, for example, highly valuableinsecticides have been developed whose effectiveness and applicability are to a large extent controlled and determined by particle size considerations. Localized concentrations of some insecticides as obtained by sprays generating particles of fifty microns diameter and greater, may cause damage a) useful life forms, such as bees and pollinating insects.

Entomologists have therefore appreciated the essential importance of effecting liquid insecticide dispersions in extremely fine particle size, wherein the required small quantity of effective insecticide is uniformly dispersed over the treated area, and in concentrations and particle'size wherein the enemy insect is effectively destroyed, without damaging effects on useful insects and other useful life. Such effective light treatments can be practically obtained by aerosol dispersions wherein the particle size of the treating material ranges in the approximate mean 'a've'rase. .of eight to twenty microns in diametenwith anoptionalor mean average of eight to ten'micron's in diameter in the case of certain insectpe'sts, while other hardier insectpests may require dispersions hav ing particle sizer'anges the approximate mean average of sixteen. to twenty microns.

' Aerosol dispersions having extremely fine and substantially homogeneous particle size have further extensive uses in fumigating, sterilizing, deodorizing medication, and scenting and conditioning room and building interiors. Aerosol treatment of rooms and interiors is markedly effective' where the particle size is properly controlled and reasonably homogeneous, since the liquid aerosol dispersion will drift and uniformly disperse through'the atmosphere of the confined space, moving into all the spaces and crevices where air currents may enter and finally be uniformly deposited above and beneath projecting surfaces which, when properly controlled, leaves no visible or objectionable deposit. The air in rooms and interiors can thusbe sterilized, fumigated, deodorized; scented and tempered by use of controlled amountsof the liquid'material containing the chemical ingredients desirable for the purpose. Building interiors and livestock may also be treated with liquid insecticides "to destroy dies and other insects'by proper aerosol treatment in controlled concentrations for either present or residual effects." Germicides, medicaments and hormones can also be effectively dispersed with highly successful effects in the treatment and medication of both plant and animal life. The effectiveness and desirability of a particular aerosol treatment is governed by the uniformity of the dispersion in proper and allowable amounts, depending in turn on the propagation of aerosol particles of controlled and substantially homogeneous size.

Monumental efforts have been devoted to the development and invention of aerosol generators which will generate a liquid aerosol dispersion of controlled and substantially uniform particle size.

, "the dispersion of 'theliquid material in gases which are so highly heat-ed'a-s to damage; the elfectiveness an usefulness of the treating "liquid, or which are cumbersome; expensive, difficult-to control and operate, or whichrequire expensivepro-pelling agents and adulterants.

In accordance with this invention, an aerosol generator-is provided which-is simple in-design and'construction, economical 'to manufacture, substantially foolproof in operation and which propagates an aerosolwhoseparticle sizemay be adjusted and regulated, 'withthe'parti'cles having an extremely high degree of size uniformity.

An'important feature of this invention 'is'the provision of an improveddispensing headcomprising a' series of stackeddispensing discs of almost any'desired number which" are preferably made of wear-resistant metal and preferably presenti'substantially smooth 'facing surfaces.

TSpticing elements are provided to space the inner peripheries of the dispensing'discs in a manner to presentthin open seams for'theadmission'of the aerosol liquid therebetween. The peripheral Tracing-portions of thejdispensing discs are pref- ."eramyiin substantially face-tof-face contact and 's'dheld' by compression members which form a part ofthe dispensing head assembly. A distributor member ?of unique design is positioned centrally of -the dispensing head and adjacent to the inner. peripheriesof 'the stacked dispensing discslfwhich' operates. to distribute the aerosol liquid supplied to the distributor.membervsub- 's'tafitially evenly anduniformly into ith'elopeh seams defined betweenlthe inner peripheral edg'es oflthe. dispensing discs.- The aerosol liqiiid'thus injected between the-adjacent surfaces of the [dispensing .di'scs, is' sheeted and filmed there- 'between as the film layers move outwardly to the disc peripheries under the impelling influence .of

the high speed rotation-of the dispensing head.

material is discharged from the disc periphe'ries' in fine aerosol .particlespossessing .re-

markable size uniformity.

'I he surface forming membersmay be fined to ancommon shaft rotated at high speed by any including spray nozzles Prior art machines and devices hereto therebetween which serves to draw the liquid aerosol material through the feed tube and into the seams defined between the inner peripheries of the dispensing discs. Means are provided to 5 control the flow of the liquid aerosol material through the feed tube and into the spaced rotating surfaces. With a given diametric size of rotating surfaces, rotating at a given speed, the particle size of the aerosol produced can be nicely regulated by the simpl expedient of controlling the amount of flow of the liquid to the dispensing -discs. The particle size of the propagated aerosol may also be varied by varying the diametric size of the dispensing discs, or by varying the speed of rotation, or both.

An object of this invention is to provide an aerosol generator designed to produce and generate an aerosol having particle size of substantial homogeniety.

Another object of this invention is to provide an aerosol generator having an improved--dispensing head which may be made to deliveralmost any desired volume of aerosol output, and by means of which the particle size ofthepropagatedaerosol-may be nicely predetermined and controlled.

Another object of this invention is. to provide an improved dispensing head of high output capacity by means of which the particle size of the-propagated aerosol may be predetermined and controlled.

' Another object of thisinvention is to'provide an aerosol generator having an improved blower assembly of high air volume output and low power consumption in cooperative combination with the dispensing 'head, the working parts of the'driving motor being fully enclosed and protected.

.Another object of this invention is to provide 40 an aerosol generator having an improved aeroso1..liquid. sup-ply assembly connected in leakproof relation to the dispensing head, the liquid sup-ply assembly having a detachable supply tank associated therewith.

A further object of this invention is to provide an aerosol; generator which is simple and compact in design and construction, which may be constructed in various sizes andfforms best suited for the particular aerosol treatment for which the generator is to be used, which may be powered an'didriven by almost any desired power unit, and whichsis highly practical: in use, economical. to

manufacture, and flexibly adapted to the various purposes of aerosol propagation- V fOther' o'bjects'and advantages of this invention will become apparent as 'this description "proceeds.

Although the characteristic features of the invention willb'e particularly-pointed out in the claims appended hereto, the invention itself, "and the manner in whichit. mayibe carried out, may

be better understood 'byir'eferring to the followingdescription takeniin connection with the 55 accompanying drawings, forming a part hereof,

' in" which .Fig. 1 is an elevational view-of, the improved generator, certain I parts. thereof being vshown in section.

7 Fig.2 is an enlarged cross sectional view of the dispensing head, this view also showing the upper por-tion of thehollow driveshaft and associated motor enclosing casing, and in addition-a frag- ;mentary portion of .the aerosol liquid supply cond -iit and -the 1-1iq1 1id-Sea1 for connecting the .nor-

" This generator unit, is preferably designed be driven by; a high speedimotor H ,fixed .to'a

mally stationary supply'conduit totherotatable same would appear when viewed along line 3-3 ofFi'g- 1f; H s.

Fig. 4 is a transverse cross-sectional 1 view or the'aerosol generatoras the same would"appear whenviewedalonglined-4 of Fig. 1. 1 Q Fig-L5 is-a plan view ofone of the spensing discs '1' 'j i 6 is a fr gmenta'rycross-sectional viewofi a portion of the dispensing disc as the samewould appear when viewed along 1ine;66 of Fig- 5. 1 Fig. 7 is a plan'view -of one of the dispensing discs of somewhat modified construction and having spaced pimples around the inner periphery to. provide for spacing of the inner peripheries of the assembled dispensing discs.- p Fig. 8 is an enlarged fragmentary cross-sectional view of the modified-dispensingv disc as the-same wouldappear when viewed along line 8- 8 of Fig.7. Y I w Fig.9 is an-enlarged fragmentary cross-sectional'view of the modified dispensing. discas the same would. appear when viewedalong line 99 0f:Fig...7..' Y i g Fig. 10 is a perspective View, partially in-cross section,:of the hub member which forms adpart of the dispensing head; and-. v

- Fig. @111; is .an. elevational. .viewqof generator. illustratinguthe' manner in may be-carried when in use: .i-u Similar. reference 'characters.-. refer to similar parts throughout the several views of the draw-.- ings andspecification. \Referring to the drawings, this improved aerosol generator may be said to comprise an outer casing assembly I having anupper section 2 which houses and .contains .the motor assembly land the fan assembly 20. .A dispensing head assembly 30 is positioned adjacenttothe open endof the upper section 2. of the casing assembly the aerosol which lit .i and is fixed to thehollow motor shaft l2. The

lowerv section 3 of the casing assemblytcontains and houses the-aerosol liquidsupply assembly 60. It willlbe appreciatedthat the casing assembly 1 may bemade'of almost any-desired shape and size best, adapted for the convenienceofthe user and the work to be performed. In the construction illustrated in Figs. 1, 4 and 11, the mid-section. of the'casing l is provided-withspaced web sections: 5 which define spaced openings 6 therebetween through which'air. maybe freelydrawn into the interior of the casing assembly I.. The web sections 5 and thespaced air openings 6 are encircled by a protective grille! to protect the interior mechanism, the upper and lower edges of the, grille] seating against spaced shoulders I formed in the casing wallto maintain the grille-band in position substantially flush with theexterior surface of the casing l. The gen,- erator may be supported upon suitable flared feet .4 associated with the lower end of the casing metal attached to the,upper casing section 2. to

facilitate transportation of the unit; 1

hollowishaft IZ and, housed within astubular suring long life to theunit. e v

motor casing.- .I 3. 1 Thelupper end of the tubular casing 3 may be closed'by%a.-,cover:.plate H. se

7 cured in 'positionas by suitablescrewswllflr-asl shown more particularly in. Figs.='l and. 2'; :rJIhe. lower: end ofwthe tubular motor casing L3,; may; be closed by asuitable closureas presented byra; bulged portion of the motor; casing; t 3," the-bulged portion terminating in a collar; 13 '5 1 lower end. of :the: motor casing. l 3 .:may? also be closed by the upper end of the fan'casing 2|. Whi'ChiWiH presently be described. The; enclosed motor.

casing prevents the collection of dust and aerosol material on the operating parts ofthe motor; and the associated motor bearings, therebyin-.

The rotatable motor shaft I2,.having a tubular passage [2' therein through' which the-aerosol liquid is conducted from the source of supply. to the dispensing head 30, is. rotatably mountedin a pair of bearing assemblies 15. Each bearing assembly is preferablybf the ball bearing type having a bearing ring lfifixed to the motor shaft l2 to rotate therewith, and a'stationary; bearingring [6. One of the bearing rings I5" is fixed to -a surrounding collar I1 associated with the cover plate [4. of the. motor ceasing. Suitable.

radially extending-webs l1 associatedwith the casingcover plate 14 may be providedto bracethe collar portion J1 and further strengthen and stifientheconstruction. The rotatable bearing ring l6 and the stationary bearing ring IB".pro1-; vide a raceway for the contained ball bearings :l 8. The ball bearings. 18 may be additionally housedbetween :bearingiseals I to retain the bearing lubricant. therebetween and insure long bearing life. The .other bearing assembly I5 is supported by the collar.v I3 at the lower endof the motor casing. .v

The blower vfanassembly '20 is fixed to rotate with the hollow motor shaft l2 directly. below the tubular motor'casin I3. The blower assembly may comprisea tubular body portion zlii'having the same, diameter as the tubular motor casing I3, and may be provided with a closed; end-wall 22 castintegrally with-the tubular body portion 2 I. 1 .The closure end wall 22 of the blower casing may befixed. directly to the motorshaft l2 and sealedthereto so that no dust or aerosol liquid can enter into. the tubular casing 21 of the fan or the tubular casing l3 of the motor. Radially ex-'- tending, scoop-shaped fan blades 23 may be integrallyattached to the tubular body 2| of the fan assembly as shown inFig. 1. The fan bladesreceive air entering the casing assembly I through the air openings Grand serve to drive the air axial 1y at considerable velocity. The inner ends of the scoop shaped'fan blades 23 extend across the vertical wall and the fan casing 2|. at an -angle roughly approximatingfli)". The lower edge 23 of thefan'blades may be'of rounded curvature with the .fan blades tapering towards. thev upper edge 23"--thereof to a relatively thin edge. The outer ends 24 of the fan blade. are square cut so as to substantially conform to the interiorwall portion 25 ofthe outer casing assembly I with a minimum of clearance therebetweem- The tubular motor casing I3 is provided'with radially extending fins I9 having curved lower end portions [9 as shown in Fig. 1. Theouter vertical edges IQ" of, the fins [9 maybe. cast integral-with the inside face of the upper section 20f the casing assembly I. The fins l9 serve as thetfan assembly 20, and serve to direct the air stream axially sothat an axial flow of the air is aeomza.

achieved as iti emerges from the. upper rim;;2: ;.oi: the casingassemblyl; .Theair stream travelling between the 'fins .19 .s'ervesto keep :the tubular. motor leasing .13 cool', .thustdissipating heat generated; by the; driving .motoi'sli. It will beeapprea ciatedsthat the fans assembly; illrotateis with the motor-:ishaft' 122 at. theisamezspeedasi the; motor, whilethemotor. casing- 113 and-.thea'ssociatedmotor: casing fins l9 :remainstationary,.with;the moton. armature contained; inuthe .motorrcasing 'l3 freetto revolve therein.

important :feature: of; this. invention .isuthe provision of an: improvedidispensing headassembly whichis shown. in detailiin Fig; 2 and; Eigsifi to 9 inclusive. The dispensing 'head'aassembly comprises essentially aseries of stacked. discs 3| of almost. any desired numberwhich are made from hardrwear-resistant metal presenting ;smooth and :polished surfaces. The i dispensing I diSCSi 3 l asformed may be substantially flan-and preferably present a truly circular outer periphery? 3| and a. circular innerperiphery 31" .as .shown more particularly iii-Figs. 5 and 7; The discs are stacked. together,. with'means provided to maintain their inner peripheriesseparated a few. thousandths of aninch to admit the aerosol liquid therebetween, the outer facing portions ."of the dispensing 1discs'. being. substantially face -toface lappedcontact and-.so held when stationary by compression .members which .form' a part of the dispensing head assembly.

L The zstacked dispensing discs are supporteduponzaazdistributor member 33 having a hubportion 342:.provided with a bore 3'4. which snugly telescopes over. the. upper. end of T the hollow motor shaft iIZ and is 'suitablysplined or otherwise secured; to "the motor shaft 12 to rotate therewith. The upper face of the distributor memberi'33 provided witha circular cavity 35 defined by a splash wall 31' ofgenerally circular contour. The motor: shaft 12' is provided with. two or more liquiddischarge openings 38 which extend radial-1y through the :tubular wall thereof. "The bores or holes -38. provide communicating passages for the aerosol liquid flowing: through the tubular passage l2- of the shaft to thexrecess cavity 3.5.? Duringthe high speed rotation of the dispensing head assembly, the aerosol liquid is .centrifugally thrown from the recess 35- overthe'splash wall 31 and-into a-surrounding cavity 55 whose outer periphery is defined by an abutment walla 39. The abutment wall. 39 is separated into- :spaced segments by radially extending narrow slits :40 through whichthe aerosolliquidmay escape. The slitrpassages 40= are sufficiently narrow: so :thatithe liquid reaching :the well '5 5: is .centrifugal'ly ejected from the entire length of the slits-4'0;

The inner periphery 3 I of lthe'dispensing discs 3lwsnuglywabuts against the outer'periphery 'offthe abutment wall 39. The lowermost: disc as shown more. particularly in. Fig.2, seats against a seal- .ing' ring 4| housedv within a conforming cavity 4:! formed-in the; flange portion 41 of :the distributor member :33. The "flangepo'rtion- 42 is provided with a peripheral head 43 against which; the lowermost disc 3'talsoseats. 7 ."The:stackeddispensing discs-3| are clamped betweenthe' flange: portion 42v of the distributor -member 33 and aildisheshaped compression member 44 which has a central hole' throughwhich the upper-end f? the motor shaft 12 snugly telescopes. Thelower face ofxthewcompression member 44 .is provided with a shallow circularrecess 45- designed .to snugly receive the upper end: of the abutment wall- 39. A sealing gasket 46 seat me .within a: conforming Cavity 45. :iinl'thfi compression member 44 is designed l Qrpressiagainst the inner. edge portion-.ofrthe top-dispensing disc 3 l ,5: thecomDression ,member. 4422 also havin 1a flange portion 41 provided with a bead 4-8. shaped to exert pressure against the topmost dispensing disc; approximately at the mid-sec tion thereof.

:It wilt be; appreciated that; when: the; dispense ing head is fully assembled; the beadportions 43and- 48 of the compression :members Y 33 and 44 serve to press the outer peripheral portions-of the. dispensing discs into substantial face etc-f ace contactzso that the outertperiphery3100f the dispensing discs. present: an almost imperceptible seamztherebetween. The: sealing rings '4 I and 46 may: be :made of rubbenor: like compositionto provide: a leak-proof seal which prevents a the escape: of aerosol. liquid between the compression members 33 and 44:and-theadjacentdispensing discs. .Aqcap. nut 53 having an internal; thread 54 is: 'screwed'to ;the:.upper end of the hollow shaft and may be'tightened to exert -pressure against the compression member 44 so that the stacked dispensing .discs 3 l :are: clamped between the bead formationsi43and 4810f 'thecompression members 33..3I1di4'4 so: that the peripheral facing portions of the discs are compressed.;- together in substantially .faceetoeface contact.

The. inner peripheral edges .2 3 I ...of the dispensing discs are maintainedi in 'spaced apart relationship '1 by suitable" spacer .elements. .As shownin Figs. 5. and 6; :thegspacer elements: may comprise thin rebent..tonguesz5fi'lcutrfrom the sheet metal from'whic'h :the discis formed,xeach tongue356 being rebent tooverlie.v the; adjacent face of the disc so that .-':when..the1:;discs =..are stackedt together in operating: relationship, the inner peripheraledgesil'f' of the discs are-maintained-rspaced: apart ai few thousandths of a-n inch; Aszanother .modification, the spacer-elementsxmay comprise: minute. pimples' fifi' and 56"-:which are stamped outialongthe inner peripheral edge of alternate discs as shown ini' Figs. .'7,; 8 and 9. it-will behnoted: that" thespaced pimples; 56 projectsli'ghtly :fromone side face of the-disc, and -thealternate *pimples 5-6 project slightly ":from :the opposite 'side of the disc. Where the spai'cingQelements': proj ectalternately from: opposite sides of the disc, only alternate discs 'ineed be: equipped with spacer elements;

:An. aerosol liquidsupply assembly 'td iscontainedcwithin theulower-section 3 of the casing assembly. 'I' and-has a. feeding connection 'with the lower 'end. of the hollow 'shaft l2. The aerosol liquid' may "be contained within a container file mad'e 'of .i either glass or metal the jar 6| 'havingia threaded-neck portion 63: adapted to be. screwed into the 'threadedfiange 64 "of a closure cap. "Crossribs 6-2 may be associated wi-ththe bottom wall of the container to facilitate attachmentand detachment thereof to the closure cap. "The-closure cap is provided with a top wall 65 which-is secured as 5 by screws 6 to a "spider frame BI which is fixed to the web portions'5 of the casing assembly las byscrews .89. A- gasket: ring 63 otrubberor like material mayxbefixed within the closure cap to provide a vleakeproof seal betwee'n the neck" portion- 63 "of thecontainer-and the closure =cap.- v l The Spider framei 61 presents a substantially solid: center 1 section: '61" -'conncted-by=webs-' [61" to the rim portion fi'l thereof. The'opening's defined rby the webs 61'" provide passages through which air i's' drawnby the fan -bl 23. The spider frame 61 is 'provided with an of the tubular shaft I2.

tainer 6|. The bleeder passages 68 and es-"are sufficiently small in diameter so thatfno aerosol liquid in any appreciable quantityfcould escape therethrough. s Y,

As shown more particularly in Figs. 1 and 2, the aerosol liquid within the "container fil; is removed through a feed tube I4"which-may 'be made of rubber, metal orthe like The'upper end of the feed tube I4 may be telescoped over the bulged collar I3 of a fitting 10'' which has a laterally extending flange II associated there'- with secured to the center section 61' of the spider frame 61 asby screws I2. The fitting 20 has a liquid passage I3" extending therethrough.

A sealing assembly is'provided'which' makes a leak-proof connection between the outletend of the fixed fitting I and the rotatable tubular shaft I2. The sealing assembly comprises a stationary part I5 which comprises a cup-shaped member I6 having an 'inturjned bottom wall 16' which is snugly fitted and sealed within a cavity provided in the center section 61' of the spider frame 61. A bearing ringfl'l formed from a carbon or other nonmetallic composition seats within the cup-shaped member; and is supported by a resilient cushion ring l3 snugly seated within the cup-shaped member :16; An axially extending liquid passage TI is provided in the bearing ring 11 which communicates with a like opening 16" i'n'the bottom wall I6 of the cup member 16. The bearing ring I'I has an overhanging flange portion I9 which seats on the cushion ring I8 and an upstanding boss portion 8|] which has a polished bearing surface 80.

A companion sealing part BI is fixed to rotate with the tubular shaft I2 and comprises a cup member having a tubular wall 82 which embraces the lower end of the shaft I 2 and'a bottom wall 83 which seats against the lower end of the shaft, the bottom wall 83 having an axial opening 83' therein which is in alignment with the passage I 2' of shaft I2 and the passage 11 of bearing member TI. A gasket ring 84 seats within a conforming groove 85 extending circumferentially around the lower end of the shaft I2. The ring 84 provides a leak-proof seal between the shaft I2 of the side wall 82 of the cap member. An aligning pin 85' may be provided to secure the cup member to the end The lower face of 'the bottom wall 83 of the cup member, which rotates with the shaft I2, has a smooth bearing fit against the bearing face 80' of the'bearin'g member 11. This bearing contact is maintained by the resilient cushion 18 supported by the spider frame 61. It will be appreciated that the cup member associated with the shaft I2 rotates while. the bearing ring 'I'I fixedwithin the spider frame 61 remains stationary. -The contact surface 80 of bearing member TI is maintained in bearing position against theretating bearing wall 83 associated with the rotating shaft I2 in a manner to provide a leakproof seal therebetween, and the small amount of wear which the bearing surface 80 receives is compensated for by the resiliency of the compressed supporting cushion I8.

In operation, current is supplied to the motor which in turn rotates the shaft I2 to'which the in a seriescf layers 0 '1'0 dispensing head" assembly 30 'is'attached. As the dispensing head rotates, air contained withinthe cavities 35 and 55 of'the dispensing head is ejected and escapes between thefclosely 1 fitted dispensing discs3I, thus creating a substantial vacuum or suction; in thehead spaces 35 and 55." ,The

vacuum thus created "draws'the aerosol liqu'id from the" container 6I' through the tubing 14 which extends into the liquid, thence through the passage '11 in thestationary part 15 and through the passa e as er the rotating part fll of the sealing ring assembly. The aerosol liquid, under the suction action created by the rotating dispensing head-flows rapidly through, the passage I2 in the tubular motor'sh'aft I2 and: escapes through the axial passages 38 in the shaft 'I2 and into the well 35 of the dispensing head The centrifugal force generated by the rotation'of the dispensing head 30 throws the aerosol liquid over the crest'of the spillway wall 3 1 against the entire'innersurfa'ce of the abutment wall 39,;

'Ihe'-"increasing centrifugal force drives the "aerosol liquidfthrough the entire length of} the numerous slit passages 49 in theabu'tment'wall '39, between' the dispensing discs at the spaced inner edges 3I"' thereo ffiand outwardlytwithin the contracting spaces between the dispensing discs 3 I. As the aerosol liquid continues to-travel outwardly between the closely fittedsurfacesof the dispensing discs 3|, the'liquid is sheeted into a series of films of minute thickness and emerges u aerosol particles substantially homogeneous in size.

The aerosol particles centrifugally discharged from the'outer periphery 3l' 'of the dispensing discs 31 will be picked up by the air stream generated by the blower 20 as the air travels through the opening 22 defined between the upper edge 2' of the casing I and the periphery of the stacked discs. The air stream travelling through the throat opening 22 changes the direction of movement of'the aerosolparticles, initially movingin the'general plane of the dispensing discspto. a

direction generally normal to the plane of the him into larger particles, even though twenty.

or more stacked dispensing discs are used to propa'gate' nineteen or more streams of aerosol particles discharging from the disc peripheries. Thefstackeddispersion discs should present their adjacent peripheral face portions in substantially surface-to-surface contact if an aerosol of relativelysmall particles of uniformsize are to be expected. The'dispersion discs 3|, while made of strong and tough metal, may be made substantially thin so that the peripheral portions thereof are held in resilient face-to-face contact by the bead'portions43 anddfl.

The dispensing discs are preferably, but not essentially, circular in form, and may vary from two to three inches in diameter to twenty or more inches in diameter. The dispersion discs should be mounted to rotateat relatively "high speed'to effect a peripheral velocity of from ap-' proximately fifty feet per second to several hundred 'feet per second and upwards, depending upon the aerosol liquid used, the particle'size to admitted-.-to--the dispensing :discs.

preciated that an increased Volume ofraerosol liqbe produced, and :the volume rate at which the aerosol liquid is: fed to the. dispensing .head.

The size of. the aerosol particlesmay 13856011- trolled by controlling the volume of aerosol liquid It will a beall- .liquid admitted to the dispensing. discs, may be conveniently controlled .by the provision, of-an adjustingr screw 49 which fits. :int the-end of the tubular feed-shaft l2, the adjusting screw-49 havingatapered endportion 50; a threaded neck portion ..52 and a head :portion- 5'! by means-..-of

which the lower tapered portion .50 .of the. screw may. be -manipula-tedto ,-control the volume of aerosol liquid permitted to discharge into the radial.tubepassages38. Aplurality of adjusting screws 49 having taperedends :50. fvarying shape may be provided for each --aerosol generator unit so that selected adjusting screws may be interchangeably applied .to the tubular: feed 7 shaft I 2 to .provide a variety of known and. predetermined dischargesettings for-the unit.

.A...dome-.shaped protective guard 90 may, be positioned directly over the dispensing headl as shown in Fig. l to prevent; inadvertent .contact withthespinning dispensing-head and also to blanknut any undesirable eddy. currents. The

dome-.shaped'guard member 90 may be supported by. flared; arms .91 attachedrtorthe upper end of the casingl .as by removable screw-.92. The supporting} arms .9 I. are. preferably made, of relatively thin metal-with their flat surfaces lying in an axial. plane. so as tonot. appreciably interfere with thecmovementof the aerosol discharged from the-unit. Where an electric motor provides the p'owersource, apower conduit 95-may be provided-which. extends through the casing..--.l and motor casing l3 andreceives the power cable -96. Aisuitable switch connection may be-provided adjacentfthe casing- I for. the convenient control of'the currentfiow to the motor.

Aerosol generators may be made-in accordance with this. invention .to. produce. aerosols of any selected particlesize .rangingirom one to two microns ,in..diameter .:up to the upper ranges-of aerosol particle sizes, andthe selected size .=of the aerosoljparticlesmay be maintained .substan- .tially uniform. Where aerosols. having particle size, of. {only a few .-.microns .is. desired, the adjacent :peripheralsfaces.ofthe dispersion discs 3 I should be polished and closely lapped-so as to present. smooth surfacesin face-tovface contact, and jthe .volume of aerosol liquid fed-between the ,discs should be controlled so-that the .pressure, exerted by .the liquid moving outwardly. betweenthe adjacent faces of the discs will not appreciably. separate the closely contacting surfaces of the-dispensing .-discs.

By. increasing the liquid flowto-the-dispensing discs,. a corresponding increasedseparating .pressure may. be exerted against-the adjacent surfaces of-thedispensing discs to. thereby increase the. size ofthe aerosol particles produced. Aerosolv generators may be made in accordance with this invention having any desired aerosol: output capacitypf the selected-particlesize :by .-in-

creasingnorndecreasing the .diametric size -'of,- the discs-and/or increasing. or decreasing 431162111131- ber. ofthe .dispensing discs. assembled into i the unitary dispensing head. 3

It willybe appreciated that this improved dispensing-head maybe .driven by any selected power limit such as an electric motor, gas .or stream turbine; combustion engine, air: cornpressor or the like, and may be madeas -asmall v compact unit for interior use or as a high capacity unit for field use. -While theblo-Wer assembly .may bevaried intype and design, a blower assembly 0f the typeabove generally'illustrated and described is particularly economicaliin power consumptionand-may be-designed to produce a high :volume, high velocity air stream which. will give substantialdirection to 'theprojeeted aerosol. Aerosol generators' constructed in accordance-Withv the teachings of-this invention are ideally suited for numerous aerosol treatments in. the. field of entomology, agronomy, animal husbandry, publichealthsanitation and medicine. r

It is understood that the principles of'thisinvention/may -be embodied in various modifications and adaptations, and it. will be accordingly appreciated-that this invention isnotlimited to the. particular embodiments described andillustrated, andthat various omissions, substitutions and changes .may be made by those skilledsin the art without departing from the teachings of this invention.

What I claim is:

1.. A machinefor converting liquids: to aerosols which. includes, a dispensing head comprising a plurality of dispensing :discs arranged-in stacked relationship, .said dispensing discsbeing substan tially of. equal exterior.- diameter" and having resilient peripheral portions and presenting a plurality-of paired filming surfaces, means :for maintaining the adjacent inner surface'areas thereofin spaced relationship and urging theadjacent peripheral surface areas thereof in :resilient. contiguous;- relationship,-- a distributor member positionedcentrally, of said dispensing discs,-.a .-tubular:shaft fixed to saidrdispensing discs and distributor member, said i tubular shaft having a dischargeoutlet-through which aerosol liquid -issupplied to said distributor member; said distributor member having an" interior "splash wallspaced from the discharge outlet in said shaft over; which the shaft discharged liquid may splash; an abutment wall. arranged in surrounding; spacedwrelationshi-p: from said splash Wall,.said abutment wallhaving a plurality of axially extending and radiating. slits extending ;determined :speed.

2. A machine for converting liquids to aerosols which includes; av dispensing head having dis- 'persion" members having resilient peripheral portions and. presenting. adjacent filming surfaces,;means 'for maintaining the'inner surface areas of't'said dispersion members in spaced relationshipand urging the adjacent peripheral surfaces .thereof inresilient contiguous relationship, a drive shaft fixed to said dispensing head,

a blower assembly-including a tubular casing having. the terminal edge. thereof terminating adjacent "toand spaced substantially directly opposite the periphery of .saiddispensing head to; define a discharge throat therebetween, a driving: mot or= within :said outeracasing for rotating. said shaft,'"s aid motor being'encased within a motor casing, ablower' fan positionedadjacent said motor casing havingradiating fan blades, straightener vanes radiating from said-motor casing operative to rectify the gaseous stream propelled by said blower fan and-to direct' the gaseous stream in a generally axial direction through said discharge throat; and means for supplying aerosol liquid to said i dispensing =head.

"A machine for converting liquids to aerosols which. includes, a dispensing head having dispersion members having resilientperipheral portions and presenting adjacent filming surfaces, means for maintaining the inner surface areas of 'said dispersion members in spaced relationship' and urging the adjacent peripheral surfaces thereof in resilient contiguous relationship, a

drive& shaft fixed to said dispensing head,fa

blower assembly including a tubular 'casinghav ing the terminal end-thereof terminating ad erative to rectify the gaseous stream propelled by said blower fan and to directthe' gaseous stream in a generally axial direction through said discharge throat, and means for supplying aerosol liquid to said dispensing head. v

4. In amachine for generating and directing a fog stream, a substantially tubular casing having? an annular wall terminating in an annular edge,g'a.rotatable head comprising a dispersion member, a hollow shaft supporting said head and communicating with said dispersion member, said headbeing disposed opposite said annular edge so as to form an annular discharge throat-between said edge and the periphery of said head, an electric motor next to said head and comprising a stator housing with a rotor therein/said rotor being'mounted on said shaft, a plurality of straightening vanes extending'generally lengthwise of said casing from said housing, blower having an impeller mounted onsaid shaft adjacent said motor housing on the side opposite said head, a support on the opposite side of "said blower from said motor, said support having a seal against which said shaft rotates, a reservoir beyond'said seal, a duct connecting said seal and arranged to draw liquid from said reservoir when the machine is in various positions between vertical and horizontal, said casing having an air inlet adjacent said blower, whereby an air stream is drawn in through said inlet by said blower and discharged past through said straightening vanes to said annular discharge throat where it picks up the liquid particles discharged from said head and delivers them directionally, substantially axially of the machine, to free atmosphere as a fog stream.

5. In a machine for generating and directing an aerosol fog stream, a substantially tubular casing having an annular wall terminating in an annular edge, a rotatable head comprising a plurality of dispersion plates having substantially smooth peripheral surfaces, resilient means for urging said dispersion plates together so that their peripheral surfaces are in substantially continuous contact throughout the entire circumferonce when the head'is'stationary, the central portions of said plates being spaced apart to form a central space, a hollow 1 shaft supporting said head and communicating with said central space, said head being so disposed opposite said annular edge so as to form an annulardischarge throat between said'edge and the peripheryofsaidhead, an-electric motor next to said headandcomprisinga stator housing with a rotor therein, said rotor'being mounted on said shaft; 2. plurality'of straightening vanes extending generally *length wise of said "casing and extending generally radially from said motor housing to said casing wall, a blower having its impeller mounted on said shaft adjacent said motor housing opposite from said head, a support adjacent said blower opposite from said motor, said support having a seal against which said shaft rotates, a reservoir beyond said seal, a duct connecting said sealzand arranged to draw liquid from said reservoir when the machine'is invarious positionsbetween ver-, ticalpand'horizontal, said casing having an air inlet adjacent; said blower, whereby. an airstream is drawn in through said inletby said'blower-and discharged past-through said straightening yanes to, said annular.dischargesthroat where it :picks up the aerosol particles-discharged from said headand delivers them directionally, substane tially;v axially of the machine, to free atmosphere as an aerosol fog stream. .a ,-,6; In a, machinefor generating and directing a fog stream, a substantiallytubular casing having an annular wall terminatnig inyan annular vedge,' a rotatable head comprising a dispersionmember, a hollow, shaft supporting said head and communicating with said dispersion member, said head being disposed opposite said: annular; edge so asto form an annular discharge throat be; tween said edge and the periphery of saidhead, anelectric motornext to said head and-comprising astator. housingwith a ,rotortherein, said rotcrbeing mounted on said shaft, said stator housing being secured to said tubular casing so as to allow an. air passage therebetween, a blower havingan. impeller mounted onsaid shaft adja-- isdrawn in through saidinletby said blowe 1-a nd discharged through the space between said stator housing and said tubular casing to said annular discharge throat where it picks up the liquid particles discharged from said head and delivers them directionally, substantially axially of the machine, to free atmosphere as a fog stream.

'7. In a machine for generating and directing an aerosol fog stream, a substantially tubular casing having an annular wall terminating in an annular edge, a rotatable head presenting a plurality of dispersion plates having resilient peripheral portions and substantially smooth peripheral surfaces, means for urging the adjacent peripheral surfaces of said dispersion plates in resilient continuous contact throughout the entire circumference when the head is stationary and for maintaining the central portions of said plates in spaced apart relation to form a central space, a hollow shaft supporting said head and communicating with said central space, said headzbeing diSPOSEdlDPPbSitGc-Sflid tannular :edge

the; adjacent: ends f; said stationary conduit and said '.tubularshaft, anzair inlet-adjacent said blowera'whereby an: air. stream is drawn in through said :inlet by'said blower and discharged through-.Wsaid annular discharge throat where it Picks upz'thesaerosol particles dischargedfr'om said head-and delivers them directionally, substantially axially of themachine, to free atmosphere' as an aerosolfog stream;

:8.?In. .a mac'hi'ne: for generating and directing an aerosol fog stream; a substantially tubular casing having .an' 'annular wall terminating in annannular. edge, a rotatable head comprising 'a pluralityof-dispersion discs presenting adjacent liquid filming surfaces, a hollow shaft supporting saidaheadand communicating with: said dispers-io'n discs, said headbeing disposed-opposite said annularedge so as .to form an annular discharge throat between said edge and the periphery of said head, an electric motor comprising a-stator housing with a'rotor therein, said rotor being mounted on said shaft-said stator housing being secured tosaid tubular casingso as =to provide air-air zpassagetlierebetween, a blower having an impeller-mounted on. said shaft adjacent said stator housing on the side-opposite said head, a liquid reservoir; a stationary conduit for drawing liquld from said-reservoir when the machine is-in-various positions between vertical and horizonta-L-means-for hermetically connecting the adjacent ends of-said stationary conduit and said tubular-shaft, an air inlet adjacent said-blower whereby anairstream is drawn in through said inletby said blower -and propelled through the space between said stator housing and said 'tubularca-sing and discharged through said "annular I discharge throat where it picks up the liquid-particles discharged from said head and delivers them directionally, substantially axially orthe machine, to' free atmosphere as .an aerosol ing :adjacentsfilming :surfacea-ahollow shat-t supporting-:said :headand; communicating withisaid dispersion discs; saiddiscs-having :therperipheries thereof; dispmcdeppusiteaaid annular sedge Isaas to form: an annular discharge cthroatrbetween :saidsedge and "the periphery of; said-. -hea-d; Jan electric motor. comprising a stator :housingghaving a rotor therein,- said-rotor-ibeing {mountedon said jshait, :a pluralityv of: straightener zvaneszextending generally radially:andslengthwise .of .said casing and: between said. casing and station hous ing, a blowerrhaving ;an impellenmounted :on.:sa;id shaft, a liquid: reservoir, -a--'stationary:-icondn'it fordrawing liquid from said ireservoir'whentthe machine is z-inz. various :posi-tions -;=be.tween ivertical and horizontal, .meanssfor hermetically aconnecting-the adjacent aendslz'ofusai'd stationary conduit andwsaid tubular shaft; an air iniet adjacent said blowerw whereby? an. air? streamic. is.:.-'drawn:: through said inlet.--.by saidwbloweriiand propelled past said" straightener :vanes" and 2 discharged through: said-annular discharge: throatdyherevit picks up .the: liquid vxpa'rticlescdischair'gedazfiom said headzandde'livers them .directionall vub stantially axially of .the machine,=tofreex=atmosphere'as'an aerosoliogstream.

- I Jon-u HESS'ION; am;-

.BEFER-ENGESGITED:

The following references are of record'-iin"'the fire-or this patent: v I

UNITED STATESTPAIIENTS Number Dateti Name- 409,978 Kisingerp- Aug. 271', 1889 930,483 Kershaw Aug;'*10,*1909 976,350 'Ehrsam'et-al Nov.:22;:1'910 1,242,445 Ittner .Oct. 9,191? 1,420,722 MacLachlan June 27,1922 1,585,393- Laughlin' May 18, 1926 1,719,869 Boydc. July 9,1929 1,735,692" Ny'rop Nov. 12,1929 1,784,853 Tifiany Dec. 16, 1930 1,892,694:'-- Carter Jan. 3, 1933 1,908,230 Fawkes Ma 9,1933 1,994,912 Hochstetter Mar. 19,"-1935 2,006,627 Cairncross July 2,1935 2,656,296:- Robertson Oct. 6, 1936 2,084,621 Norris June 22, 1937 2,157,416 Kjos May- 9, 1939 2,251 457" Lee Aug."'5,-1941 FOREIGN. PATENTS Number Country Date 131,306 Switzerland i Apr.,;16,*1929 

